Specimen-orientated radiography helps define excision margins of malignant lesions detected by breast screening.

Eighty patients with impalpable breast lesions detected by mammographic screening underwent hookwire-guided wide local excision. Excision specimens were orientated with Ligaclips and submitted to radiography; if, on the specimen radiograph, the mammographic lesion crossed any visible margin, further tissue was excised. Clear histological margins were obtained on the initial excision in 52 (68 per cent) of 77 carcinomas. After inspection of the orientated specimen radiograph, further tissue was excised from 22 patients; this significantly increased the rate of complete excision to 86 per cent (P < 0.01). Significantly more patients with invasive cancer had a complete excision than those with ductal carcinoma in situ (52 of 57 versus 14 of 20, P < 0.02).